Prospective observational study to evaluate the clinical and biological safety profile of pyronaridine–artesunate in a rural health district in Burkina Faso

Abstract The assessment in real‐life conditions of the safety and efficacy of new antimalarial drugs is of greatest interest. This study aimed to monitor and evaluate both clinical and biological safety of pyronaridine‐artesunate (PA) in real‐life conditions in Burkina Faso's health system. This was a single‐arm, open‐label study, where patients attending Nanoro health facilities with uncomplicated malaria were consented to be part of a cohort event monitoring (CEM). At inclusion (day‐0), PA was administered orally once a day for 3 days. Patients spontaneous reported any clinical adverse events (AEs) occurring within 28 days following the treatment. Additionally, the study focused on AEs of special interest (AESI), namely clinical signs related to hepatotoxicity and increased alanine aminotransferase (ALT) and aspartate aminotransferase (AST). A nested subset of patients with blood sample collection at day‐0 and day‐7 were monitored to investigate the effect of PA on biochemistry parameters. From September 2017 to October 2018, 2786 patients were treated with PA. About 97.8% (2720/2786) of patients did not report any AE. The most commonly reported events were respiratory, thoracic, and mediastinal disorders (8.3 per 1000), infections and infestations (7.9 per 1000), and gastrointestinal disorders (7.2 per 1000). No clinical or biological hepatotoxicity event related to PA was reported during the follow‐up. Changes in biochemistry parameters remained within laboratory reference ranges. The study showed that PA is a well‐tolerated drug and should be considered as a good option by malaria control programs in countries where existing first‐line antimalarial drugs are continuously threatened by the emergence of drug resistance.


| BACKG ROU N D
With the contribution of international organizations such as Medicines for Malaria Venture (MMV) and other public-private partnerships, new effective and well-tolerated antimalarial drugs for large-scale use are getting available on the market. 1 These new antimalarial drugs, as well as those already on the market, were developed to provide countries with rational approaches for decisionmaking on the prioritization, selection, and adoption of antimalarial treatment that is appropriate for their health systems. 2 In addition to planning the deployment of these new interventions, it is also important to consolidate their safety of use under real-life conditions. 3 Traditionally, Phase I, II, and III controlled and randomized clinical trials conducted by researchers are usually well funded and provide baseline data on antimalarial drugs efficacy and safety before they are marketed. In sub-Saharan Africa (SSA), these new antimalarial drugs are often introduced into health systems through national policy decisions, often based on data from Phase I, II, and III trials. Nevertheless, the identification of rare or non-detected adverse drug reactions (ADRs) during the drug development process and the establishment of the efficacy and safety of these drugs are achieved through post-marketing surveillance. However, due to the poor performance of well-established pharmacovigilance systems in malaria-endemic countries, it is very difficult for SSA countries to set up large-scale Phase IV studies for drug monitoring in real-life conditions to guide national policy decisions. [4][5][6][7] In Burkina Faso, since 2008, fixed-dose artemisinin-based combination therapies (ACTs) were adopted as treatment for uncomplicated malaria. 8 Based on data available (cost-effectiveness) on these ACTs, artesunate-amodiaquine (ASAQ), artemether-lumefantrine (AL), and dihydroartemisinin-piperaquine (DHA-PQP) were adopted by policies makers as first-line drugs for the treatment of uncomplicated malaria. 8 Currently, with the scaling-up of Seasonal Malaria Chemoprevention (SMC) among children under 5 years of age in the country, the treatment of uncomplicated malaria in this age group should no longer include either amodiaquine or combination drugs containing amodiaquine, especially during the high transmission period of malaria (SMC period). 9 In such context, AL and DHA-PQP remain the available drugs for the management of uncomplicated malaria cases. A recently published study seemed to point out an inadequate efficacy of AL at day 28. 10 This result should be taken with caution as another publication, concluded that there is no convincing evidence in the articles reviewed that multidrug resistance has emerged in Burkina Faso, in particular amodiaquine, lumefantrine, and piperaquine resistance. 11 In addition to conducting urgently other studies (with the recommended monitoring and quality control of slide reading 11 ) to confirm or refute the findings on the emergence of plasmodium resistance to AL, it is also crucial and urgent to find an alternative drug to reduce the therapeutic pressure on AL and DHA-PQP (an important source of antimalarial drug resistance) and to replace ASAQ in order to allow the diversification of first-line malaria treatments. Pyronaridine-artesunate (PA) a fixed-dose ACT, represents the first ACT to have been validated by a stringent regulatory authority for the treatment of Plasmodium falciparum and blood-stage P. vivax according to multicenter clinical studies in Africa and Asia. 12 Randomized controlled trials carried out in malaria-endemic countries to evaluate the efficacy of ACTs in the treatment of uncomplicated P. falciparum demonstrated that PA is equivalent to the other marketed ACTs. 13,14 Furthermore, these studies showed that PA is generally well tolerated. [13][14][15][16][17] The safety warning that was reported with the PA use was a transient increase of hepatic transaminases, 13,14,16,17 without any clinical signs or symptoms of hepatotoxicity. 13,18,19 Therefore, WHO recommends malaria-endemic countries to include PA in their national treatment guidelines. 12 However, this deployment should be conducted under a strong pharmacovigilance system as required for the introduction of all new medicines. 3 Such data are required to guide National Malaria Control Program (NMCP) for the adoption of new ACTs and to provide more option for prescription, especially in areas where there is more than one ACT in the policy. To fill the gap of this shortage of safety data, this study aimed at monitoring and evaluating both the clinical and biological safety of PA used in real-life conditions in the health system in Burkina Faso. In other words, there were a primary objective that consisted to evaluate the clinical safety of PA when used under usual conditions among patients with uncomplicated malaria, and a main secondary objective that consisted of an intensive assessment of a nested subset of patients (nested cohort or active group) to evaluate the effect of the administration of PA on blood biochemistry parameters.

| Study setting
The study was carried out from September 2017 to October 2018 in the health district of Nanoro through the Health and Demographic Surveillance System (HDSS). 20 The HDSS of Nanoro is on the INESS (INDEPTH Effectiveness and Safety Studies) platform and has a good experience in effectiveness and safety studies on antimalarial drugs. 21,22 The HDSS area is located in rural setting, Central-west of the country. The Nanoro HDSS covers a catchment area of 594. 3  cases. In addition, the study area is characterized by a marked seasonality of malaria transmission 23 making it an appropriate place for SMC implementation. Currently, ASAQ, AL, and DHA-PQP are the first-line treatments for uncomplicated malaria and ASAQ and AL are provided free of charge to children less than 5 years of age. 24 PA is the latest ACT to be registered in the Burkina Faso health system.
From a previous study, the complete adherence level to antimalarial drugs in the Nanoro HDSS area is satisfactory and was estimated at 86%. 25

| Study design and patients
This was a single-arm, open-label observational, non-comparative phase IV study. All patients regardless of gender and age attending the health facilities in the Nanoro HDSS catchment area and for whom a diagnosis of uncomplicated malaria was posed (or suspected) by the public sector health care workers (HCWs) were invited to participate in the study. Patients were consented to be part of a cohort event monitoring (CEM). All consented participants (main cohort) were asked to return voluntarily to health facilities and to spontaneously report any occurrence of adverse events. Eligible patients were aged over 6 months, weighed more than 5 kg and were able to take oral medications, and signed informed consent (a parent or guardian consented for children below 18 years old). Patients were excluded if they had any of the following: the presence of clinical signs or symptoms of hepatic injury (such as nausea and abdominal pain associated with jaundice) or known to have severe liver disease (i.e., decompensated cirrhosis, Child-Pugh stage 3 or 4); known to be pregnant or lactating; severe malaria; known allergy to artemisinin and/or to pyronaridine. A nested subset of patients (nested cohort) with blood sample collection at day-0 and day-7 were monitored to investigate the effect of PA on blood biochemistry parameters.
Shin Poong Pharmaceuticals Limited donated PA (Pyramax for brand name) but did not have any role in reviewing the protocol or the manuscript.

| Enrolment and study procedures
At the enrolment visit (day 0), in both groups, data on medical and drug history were obtained from each eligible patient and were recorded on an individual case report form (CRF). For each patient, a detailed clinical examination was performed by the HCWs and the findings were recorded on the appropriate CRF. Data on concomitant medications for each patient were also collected.
Patients included in both passive and active monitoring cohorts were requested to return voluntarily to health facilities and to spontaneously report any AEs occurring within 28 days after the administration of the first dose of PA, whereas patients included only in the active monitoring cohort had a scheduled follow up visit at day 7 (±2 days) at health facility and home visit at day 28. For the latter group, data on clinical conditions and concomitant treatments were collected at each scheduled visit. Additionally, blood smears for thick and thin film and blood spot was systematically obtained on days 0 before drug administration and day 7 after drug administration. Venous blood samples were collected on day 0 before drug administration and day 7 after drug administration. Then, plasma samples were processed to investigate specific liver function tests (LFTs), namely Alanine aminotransferase (ALT), Aspartate aminotransferase (AST), total bilirubin, as well as renal function parameters namely creatinine and urea. Blood glucose was also measured.
In case of unscheduled visit or whether the patient returned voluntarily to spontaneously report an adverse event within the 28 days after PA administration, data on clinical condition and concomitant treatments were collected. Additionally, blood smears for thick and thin film were collected and a venous blood sample was drawn for biological investigation according to the clinical judgment of the study physician.
Although in Burkina Faso ACTs are recommended for pregnant women in the second and third trimester of pregnancy, 8 female patients were encouraged to inform the study team if they get pregnant within a period of 2 months after the start of the PA treatment.

| Study drug administration
For enrolled patients, PA was administered every 24 h from the first administration for 3 days. The first dose (day 0) was administrated under direct supervision of a HCW at the health facilities. After drug intake, patients were observed 60 min. For those who vomited within 30 min, a complete dose was re-administered, whereas for those who experienced vomiting within 30-60 min, a half dose was re-administered. Re-administration was attempted only once. Then, HCW explained to the patients how to take the second and third doses at home after 24 h (day 1) and after 48 h (day 2) from the initiation of the treatment. PA was administered according to the patient body weight. Two types of presentation of PA were used to facilitate the dosing and administration: sachet (granules) for children under 20 kg and tablets for children and adults weighting more than 20 kg.
The tablet presentation was dosed at 180/60 mg of PA, whereas the sachet presentation was dosed at 60/20 mg of PA. Daily dosing according to the weight is shown in Table 1.

| Follow-up for detection of adverse events
Patients in the active monitoring cohort had a scheduled follow-up visit on day 7 (±2 days) at the health facility. During this visit, the treatment adherence, that is, patients who complied with the recommended treatment according to age, was verified retrospectively through self-reporting. Additionally, the occurrence of an AE between the drug intake and the day of the visit was reported by the

| Study outcome
The study's main outcome of interest was both clinical and biological safety within the 28 days after starting PA treatment. The clinical outcome (incidence of clinical AE) was evaluated through the analysis of the AEs captured by the study clinical team; whereas biological safety was defined as any significant change in liver transaminases values (elevated AST/ALT). Safety was assessed in all patients who received at least one dose of PA. Special attention was given to the AEs classified as severe and/or adverse events of special interest (AESI) related to hepatotoxicity (jaundice, dark urine, putty/mastic stool, worsening of fatigue, nausea, vomiting, anorexia, abdominal pain, itching, rash, spontaneous bruising, or appearance of red spots). Serious liver reactions and hypersensitivity were also considered as an outcome of interest (AESI).
Safety outcomes also included any significant change in the total bilirubin, creatinine, and urea values.

| Data management and analysis
For the CEM for the active or nested cohort, all visit data were cap-

| Cohort composition and baseline characteristics
A total of 2832 patients with suspected uncomplicated malaria were screened to be enrolled in the study, and 2786 (98.4%) patients were included. Of these, 1761 agreed to be in the main cohort (passive group), whereas 1025 agreed to be in a nested cohort (active group).

| Adverse events following the administration of the first dose (within 1 h after drug administration)
No patient was excluded at day 0 for repeated vomiting after drug intake. However

| Reported adverse events during the 28 days of follow-up
During the follow-up period, the majority of patients (97.8%

Materials.
The administrated treatment was well tolerated in general.
Thirteen adverse events were assessed by study clinicians to be related to the study drug (Table 6). No serious adverse events were assessed to be related to PA. More interestingly, no hepatotoxicity event related to PA was reported during the study period. However, one patient experienced an ascites due to a splenic abscess. This adverse event was not related to PA. Another patient also presented after severe malaria, a hepatic cytolysis that investigations concluded to a cytolysis caused by malaria infection that spontaneously was resolved.

| Change in biochemistry parameters between day 0 and day 7
In general, the median biochemical values of biochemistry parameters on day 7 after PA treatment were low compared with the baseline values on day 0 ( Figures S1-S3). All the six biochemistry parameters on day 7 post-treatment were significantly low compared with the baseline values on day 0 among participants.

Figure 1 showed what happened to the patients with increased
LFTs before treatment. All patients who had elevated ALT prior to study drug experienced a significant decrease in ALT values at day 7. Likewise, patients who had elevated AST prior to study drug showed a significant decrease in AST values on day 7. But individually, there were three patients, who did not have a decrease in AST levels.  to these previous studies and malaria symptoms. 13,14,16,19,28 This study supports what has been observed with PA safety up until now.

| DISCUSS ION
In   antimalarial drug (using the same methodology as described in our study) suggested that the low rate of AE reported in Phase IV study than Phase II and III could be explained by the fact of anxiety of the patient taking a new drug. In addition, the blinded condition in which such drugs are administered may cause an increase of AE reporting. 22 Moreover, in this study the fact that more than half of the patient was children aged under 5 years of age raised the challenge to obtain reliable safety recall information regarding certain AEs. This could also explain the weakness of the AEs recorded.
Another weakness of this study was related to the study design which was a single arm, open-label, which could lead to report adverse effects for which symptoms presented at the health facility before treatment as AE which were not "new or worsening events" post-treatment.

| CON CLUS ION
In a context where existing first-line antimalarial drugs are continuously threatened by the emergence of malaria parasite resistance to antimalarial drugs, the evaluation of the newly registered antimalarial drug, PA, showed a good safety profile in patients of all the age F I G U R E 1 Evolution of liver function tests in patients whose ALT and AST were increased before treatment.
groups in our study. Therefore, PA has deserve of being added to the list of existing first-line treatments of uncomplicated malaria in Burkina Faso. These findings are useful for the malaria control program in countries for policy decision-making.

AUTH O R S ' CO NTR I B UTI O N S
TH, TCM, SP, VI, RT, BR, and BF contributed to protocol development. TH, TCM, SP, VI, RT, CA, YWI, TMC, HSF, NAD BR, and BF contributed to data collection and the overall implementation of the study. RT, TH, PS, and YWI worked on data analysis and interpretation of the data. RT and TH drafted the manuscript and all authors read and approved the final manuscript.

ACK N OWLED G M ENTS
We are very grateful to all participants who consented to be part of the study. We thank everyone who supported this study directly or indirectly through fieldwork, data collection, or analysis support. Foundation.

FU N D I N G I N FO R M ATI O N
The study was sponsored by the INDEPTH Network as part of the funding for the INESS program.

D I SCLOS U R E
The authors report no conflicts of interest in this work.

DATA AVA I L A B I L I T Y S TAT E M E N T
All data generated or analyzed during this study are available at the Clinical Research Unit of Nanoro (CRUN) data repository and shareable upon request addressed to the head of the CRUN.

E TH I C S A PPROVA L S TATEM ENT
The protocol was approved by the institutional ethics commit-

PATI ENT CO N S ENT S TATEM ENT
Written informed consent was obtained from all patients or legal guardians before performing any study-related activity.